mobile scale (conveyor)

hello everyone, i need to design a small conveyor (5m) which is able to move back and forward and precisely stop in predetermined positions. it needs to be able to weight the product it carries.
the systems works as follow:
1. a bucket is placed on the conveyor which then moves to predetermined positions along its length so that a predetermined quantity of material (powder) can be placed inside the bucket (this is why the conveyor system needs to have an integrated scale).
what type of mechanism can i use to move the conveyor. i cannot use the traditional belt conveyor.
i can buy a scale unit off the shelf but how can i move it back and forward?
what type of drive/motor would be most suitable for this type of operation (i need to change its direction and speed easily so that i can accurately move the scale)?
thanks,
Mario

Im not to clear on your question, but I am thinking you can buy bucket conveyors with built in scales that can be run horizontally. The drive would have to too suit the combined weight of bucket and material - Standard motors tend to be 3phase 240V - 50Hz

Basically i can not understand your question but i personally recommend to proffered belt scale to produce conveyor scales with superior accuracy.....single idler scales are also used for the best accuracy